Reactive blending of functionalized acrylic rubbers and epoxy resins

A high molecular weight acrylonitrile/butadiene/methacrylic acid (Nipol 1472) rubber is chosen to control processability and mechanical properties of a TGDDM (tetra glycidyl diphenyl methane) based epoxy resin formulation for aerospace composite applications. The physical blend of rubber and epoxy resin, achieved by dissolution of all the components in a common solvent, forms a heterogeneous system after solvent removal and presents coarse phase separation during cure that impairs any practical relevance of this material. A marked improvement of rubberepoxy miscibility is achieved by reactive blending (‘pre-reaction’) the epoxy oligomer with the functional groups present in the rubber. The epoxy-rubber ‘adduct’ so obtained appears as a homogeneous system at room temperature and also after compounding with the curing agent. Depending on the nature and extent of interactions developed between the rubber and the epoxy resin during ‘pre-reaction,’ materials with different resin flow characteristics, distinctive morphologies and mechanical properties after curing were obtained. The effect of ‘pre-reaction’ on the resin cure reaction kinetics has been also investigated.

[1]  G. Spadaro,et al.  Cure Kinetics of a Tetrafunctional Rubber Modified Epoxy-amine System , 2000 .

[2]  G. Spadaro,et al.  Cure behaviour of epoxy resin matrices for carbon fibre composites , 1999 .

[3]  Reza Bagheri,et al.  Role of blend morphology in rubber-toughened polymers , 1996, Journal of Materials Science.

[4]  A. Vázquez,et al.  Rubber-modified thermosets: Prediction of the particle size distribution of dispersed domains , 1987 .

[5]  T. T. Wang,et al.  Phase separation behavior of rubber‐modified epoxies , 1981 .

[6]  J. K. Gillham,et al.  Rubber-Modified Epoxies: Transitions and Morphology. , 1981 .

[7]  M. El-Aasser,et al.  The role of dispersed phase morphology on toughening of epoxies , 1997 .

[8]  Sung Tae Kim,et al.  Multi-phase toughened epoxy with poly(ether sulphone) and carboxyl-terminated butadiene-acrylonitrile rubber , 1996, Journal of Materials Science.

[9]  Takashi Inoue,et al.  Phase separation and apparent phase dissolution during cure process of thermoset/thermoplastic blend , 1995 .

[10]  Mu-Shih Lin,et al.  Mechanical behaviours of fully and semi-interpenetrating polymer networks based on epoxy and acrylics , 1995 .

[11]  A. A. Collyer.  Rubber toughened engineering plastics , 1994 .

[12]  S. D. Jenkins,et al.  Dielectric, mechanical and rheological studies of phase separation and cure of a thermoplastic modified epoxy resin: incorporation of reactively terminated polysulfones , 1993 .

[13]  D. R. Moore,et al.  Laboratory-scale screening of mechanical properties of resins and composites: Relevance to composites for aerospace applications , 1991 .

[14]  J. Hedrick,et al.  Chemical modification of matrix resin networks with engineering thermoplastics: 1. Synthesis, morphology, physical behaviour and toughening mechanisms of poly(arylene ether sulphone) modified epoxy networks , 1991 .

[15]  J. Pascault,et al.  Rubber‐modified epoxies. I. Influence of carboxyl‐terminated butadiene‐acrylonitrile random copolymers (CTBN) on the polymerization and phase separation processes , 1990 .

[16]  J. Hinkley,et al.  Chemorheology of an epoxy resin system under isothermal curing , 1990 .

[17]  J. G. Williams,et al.  Fracture Mechanics of Polymers , 1984 .